This invention relates to vinylized epoxy resins such as vinyl ester resins, and in particular, to vinylized epoxy resins which comprise polymerizates contained therein.
Vinylized epoxy resins such as vinyl ester resins comprise a well known class of thermosettable polymers. Such vinyl ester resins possess excellent physical and chemical properties, and are particularly useful as adhesives, in corrosion-resistant applications such as when formulated as fiber-reinforced plastic structures, as protective coatings for a variety of substrates, laminates, molding compositions, encapsulants, etc. Typical formulations comprising vinyl ester resins include plastic composite sheet molding compounds, resin transfer moldings and hand lay ups. For example, such resins are dissolved in a solvent or reactive diluent such as styrene, applied to a substrate, and cured.
Vinyl ester resins are typically prepared by reacting an unsaturated monocarboxylic acid with an epoxy resin such that a resin containing the characteristic vinyl ester moiety is provided. The physical properties of the vinyl ester resins will typically depend upon factors such as the epoxy reactants and the copolymerizable monomers which are employed, as well as the presence of various inert reinforcing agents such as glass fibers, carbon fibers, clays, etc.
Vinyl ester resins having improved impact resistances are disclosed in U.S. Pat. Nos. 3,674,893 and 3,892,819. These references disclose vinyl ester resins which are blended with unsaturated polydiene elastomers and are reacted or cured under conditions such that polydiene grafts are provided to the vinyl ester resins. While these references disclose compositions which exhibit excellent impact and mechanical properties, the heat distortion temperatures of such compositions is not as high as would be desirable.
In view of the deficiencies of the prior art it would be highly desirable to prepare vinyl ester resin compositions capable of exhibiting good mechanical properties, having high heat distortion temperatures, and providing cured products exhibiting reduced shrinkage and improved surface appearance.